Liquid fuel burner



Dec. 2, 1941 K. P. BRACE LIQUID FUEL BURNER 2 Sheets-Sheet 1 Filed June 29, 1938' INVENTOR. K E MPER F? BRHCE 71k 97 15, ATTORNEYS Dec. 2,1941.

K P. BRACE Filed June 29, '1 2 Sheets-Sheet 2 0009 000000 00000000 000000000 0000000000 000000000 oooooooo INVENTOR. KE PERPBRHQE BY ATTORNEYS,

Patented Dec 2,1941

' UNITED STATES PATENT OFFICE LIQUID FUEL BURNER Kemper P. Brace, South Bend, Ind assignor to International Engineering Com, Chicago, 111., a corporation of Illinois Application June 29, 1938, Serial No. 216,434 (01.158-96) 2 Claims.

One of the objects of the invention is to provide a liquid fuel burner which is eflicient and safe in operation and at the same time extremely simple and cheap to construct. According to one desirable arrangement the burner includes no moving parts except the oil valves and their controls.

Another object of the invention is to provide a liquid fuel burner operative at either high or low rating. Preferably the burner operates constantly and changes from high to low rating under the control of a thermostat.

Another object of the invention is to provide a liquid fuel burner in which the fuel supply is shut ofi upon the accumulation of a predetermined amount of unburned fuel. According to one desirable arrangement fuel is supplied to the burner through a constant level float chamber burner;

Figure 3 is a section on the line 3-3 of Figure 2;

Figure 4 is a section with parts in elevation of the constant level chamber and fuel cut off mechanism; and

Figure 5 is a section through the fuel control valve.

Figure 1 illustrates a heating furnace ill having its combustion space connected to a stack or other draft producing means, not shown, and formed with provisions for heating a transfer medium to conduct heat to a dwelling room or other space to be heated. The front of the furnace has a fire door l2 formed with an adjustable shutter opening H and has at its lower part an ash pit [6 open at its outer end.

The burner comprises a plate l8 fitting over and secured to the ash pit and having a central opening 20. A tube 22 is secured to the plate I! in register with the opening and extends into the furnace, a partition 24 formed with a central opening being secured in the tube intermediate its ends and the innerend of the tube being lined with refractory material 26. All the lower part of the central opening the' partition 24 is formed with an outwardly extending flange 28 and has a plurality of brackets 30 spaced from its inner side around the central inwardly through the plate I8 and downwardly through the tube 22 to terminate just above the burner element. The pipe 36 is connected through a manual shut-oil valve 38 and a two position valve 40 to a constant level fuel chamber 42 which is mounted on'the front of the plate [8. Fuel is supplied to the chamber 42 through a pipe 44 from a tank or other suitable source under the control of a valve 46 controlled by a float 48 (Figure 4). l

The two position valve 40, as best seen in Figure 5, includes a slidably mounted rod 50 projecting through one end of the valve housing and having one end pointed to project irlto and variable to restrict a port 52. The rod 50 carries a collar 54 and a spring 56 engages the collar and a flange in the valve body to urge the valve away from the port 52. A cap 58 is screw threaded to the end of the valve body around the rod 50 and the rod carries a nut 60 outside of and engageable with the cap.

The cap 58 and nut 60 provide respectively high and low adjustments to determine the high and low positions of the valve. The high adjustment is effected by screwing the cap more or less onto the body to limit outward movement of the rod5ll by engagement of collar 54 with the cap thereby to limit the maximum opening movement of the valve. The low adjustment is effected by screwing the nut 60 more or less onto the rod 50 so that the nut will engage the cap 58 to limit inward closing movement of the valve.

The valve is controlled by a bimetal strip 62 secured at one end to an insulating bracket 64 on the float chamber 42 and with its other end engageable with the end of rod 5| or nut 6|. A heating coil 66 is wound around the strip 62 connected at one end to the strip and at its other end to a wire I. As shown the strip 2 is grounded through the chamber 42 but it will be understood that a two wire system could be used instead of grounding one wire if desired.

The wire 68 is connected, as best seen in Figure 1, to one side of a grounded transformer 10 through a conventional room thermostat 12. when the room temperature drops below a predetermined degree the thermostat closes and when it is above a predetermined degree the thermostat opens.

In operation the float chamber is connected to a suitable oil supply and the manual valve 38 is opened so that oil will flow through pipe 36 to the element 32. The burner may now be lighted by touching a match or the like to the element 32, the stack draft drawing air through the openings 34 to vaporize oil and the mixture of air and oil burning in the tube 22 and in the combustion space of the furnace.

If the room temperature is above the value for which thermostat I2 is set it will be open and the heating coil 66 will be de-energized. At this time the strip 62 is cool and deflects downwardly to press the valve 50 to the low position as shown in Figure 5 in which the flow of oil is restricted. In this position not enough oil will be supplied to saturate the entire element 32 and the flame will burn over only a portion of its area to provide lowrating operation.

Should the room temperature drop to a value belowthat for which thermostat I2 is set the coil 66 will be energized to heat strip 82 and cause it to deflect upwardly. Valve rod 50 will be raised by spring 58 to open port 52 further and increase the supply of oil so that a greater area of element 32 will be saturated and the flame will be increased. Preferably the high and low operations are adjusted through cap 58 and nut 60 so that the low rating is slightly less than the normal demand and the high rating is slightly greater. Thus by alternating between high and low rating under the influence of the thermostat the room temperature is kept at the desired value.

In the event of flame failure for any reason it is desirable to shut off the flow of oil until the burner has been relighted. According to the present invention this is accomplished by connecting a pipe 14 to the tube 22 just in front of the partition 24 to carry oif any unburned oil dripping from the element 32 or collecting in the tube 22. The pipe M extends through the plate II to discharge into a receptacle I! which is secured at one side to a rod 18 journaled in brackets II on the front of the plate. The rod 18 has a right angular extension 82 connected by a link 84 to one end of a lever I which is pivoted at its other end on the top of the chamber 42. A pin 88 is connected to the lever 88 and extends through the top of chamber 42 in register with the float valve 46, a spring 90 urging the lever upwardly and normally balancing the weight of the receptacle It.

Normally the, spring holds the pin 88 out of engagement with the float valve so that the float valve opens and closes under the sole control of the float 48. After a predetermined quantity of oil has accumulated in the receptacle 16 its weight will be suflicient to overcome. the spring and press the rod 88 against the valve 46 to hold it closed regardless of the action of the float. Thus the oil supply will be cut oil until the reservoir 16 has been emptied and the burner relighted.

While one embodiment of the invention has been shown and described in detail it will be understood that many changes might be made therein and it is not intended to limit the scope of the invention to the exact form shown nor otherwise than by the terms of the appended claims.

' What is claimed is:

1. A liquid fuel burner comprising a burner tube adapted to extend into the combustion chamber of a furnace, a partition in said tube having an opening therein, a porous element fltting in said opening and formed with air passages therethrough, a supporting bracket on one side of the partition on which said element rests, brackets on the other side of the partition engaging the surface of said element to hold it in place, and means to supply liquid fuel to said element.

2. A liquid fuel burner comprising a supporting plate having an opening therein, a burner tube secured to the plate in register with the opening and projecting from one side'of the plate, a porous element in said tube formed with air passages therethrough, aconstant level chamber secured to the other side of the plate and having a floatcontrolled valve therein, a conduit extending from said chamber to a point adjacent the porous element to supply fuelto the porous element, a container movably mounted below the constant level chamber on said other side of the plate, a conduit to conduct unvaporized fuel from the porous element to said container, and linkage operated by movement of the container in response to a predetermined weight of fuel therein to close said float-controlled valve.

KEMPER P. BRACE. 

